U.S. patent number 6,077,263 [Application Number 09/130,204] was granted by the patent office on 2000-06-20 for vertebral osteosynthetic system.
This patent grant is currently assigned to Aesculap AG & Co. KG. Invention is credited to Marc Ameil, Jean Huppert, Jean-Louis Jermann, Thierry Marnay.
United States Patent |
6,077,263 |
Ameil , et al. |
June 20, 2000 |
Vertebral osteosynthetic system
Abstract
A spinal implant system including a spinal rod, a first clasp
and a second clasp, a connecting element having a head and a shank
connecting the first and second clasps, a first fastener for
fastening the body of the first clasp to the spinal rod, a second
fastener for fastening the shank of the connecting element to the
body of the first clasp and a retainer for retaining the second
clasp onto the head of the connecting element so that the second
clasp can disengage itself from the head only in a direction toward
the first clasp. The first clasp is adapted to be fixed to the
vertebrae by a hook thereon. The second clasp is adapted to be
fixed to the vertebrae by a hook thereon.
Inventors: |
Ameil; Marc (Reims,
FR), Huppert; Jean (L'Etrat, FR), Jermann;
Jean-Louis (Chaumont, FR), Marnay; Thierry
(Montpellier, FR) |
Assignee: |
Aesculap AG & Co. KG
(Tuttlingen, DE)
|
Family
ID: |
9510274 |
Appl.
No.: |
09/130,204 |
Filed: |
August 4, 1998 |
Foreign Application Priority Data
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Aug 13, 1997 [FR] |
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97 10327 |
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Current U.S.
Class: |
606/276 |
Current CPC
Class: |
A61B
17/7032 (20130101); A61B 17/7047 (20130101); A61B
17/7004 (20130101); A61B 17/7041 (20130101); A61B
2017/00429 (20130101); A61B 2017/00433 (20130101) |
Current International
Class: |
A61B
17/70 (20060101); A61B 17/00 (20060101); A61B
017/56 () |
Field of
Search: |
;606/60,61,79,73,59,57,69,70,71 ;623/17 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Buiz; Michael
Assistant Examiner: Ho; (Jackie) Tan-Uyen T.
Attorney, Agent or Firm: Harrison & Egbert
Claims
What is claimed is:
1. A spinal implant system comprising:
a spinal rod;
a first clasp and a second clasp having respectively a first and a
second body and a first and a second hook, said first clasp being
adapted to be fixed to a vertebrae by said first hook and said
second clasp being adapted to be fixed to the vertebrae by said
second hook;
a connecting element comprising a head and a shank, said connecting
element connecting said first and second clasps;
a first fastening means for fastening said first body to said
spinal rod;
a second fastening means for fastening said shank to said first
body; and
a retaining means for retaining said second clasp onto said head so
that said second clasp, in the retaining position, can disengage
itself from said head only in a direction toward said first clasp,
said first body defining a recess for reception of said shank, said
recess having a bottom and two lateral walls, said recess defining
first and second lateral openings and an upper opening, said bottom
being on a side of said first hook, said upper opening being on a
side opposite to said first hook such that said connecting element
can be inserted and removed through said upper opening, said second
fastening means having a blocking screw for blocking said shank in
said recess, said blocking screw having a screwing axis
perpendicular to said shank and cooperative with a tapped hole
formed in said two lateral walls.
2. The spinal implant system according to claim 1, wherein a
surface of said shank is smooth.
3. The spinal implant system according to claim 1, wherein said
shank has a roughened surface adjacent an end thereof.
4. The spinal implant system according to claim 1, wherein said
screwing axis of said blocking screw is oblique or perpendicular
with respect to a plane defined by parallel axes of said spinal rod
and said connection shaft.
5. The spinal implant system according to claim 1, wherein said
bottom is of a semi-circular cross section and corresponds to a
diameter of said shank of said connecting element.
6. The spinal implant system according to claim 1, wherein said
first clasp has a split threaded head for receiving said spinal
rod, said split threaded head having a nut threadedly received
therein for immobilizing said spinal rod.
7. The spinal implant system according to claim 6, wherein said
nut, said recess and said blocking screw are constructed to prevent
an exit of said blocking screw.
8. The spinal implant system according to claim 7, wherein said nut
is supported on said blocking screw.
9. The spinal implant system according to claim 6, wherein said
screwing axis of said blocking screw is parallel to or oblique with
respect to an axis of said split threaded head.
10. The spinal implant system according to claim 1, wherein said
head of said connecting element comprises a cylindrical or conical
head which is received in a complementary receptacle provided in
the respective clasp.
11. The spinal implant system according to claim 1, wherein said
recess is formed in a base of the first clasp.
12. The spinal implant system according to claim 1, wherein said
recess is formed in a collar which is held attached to said first
clasp.
13. The spinal implant system according to claim 12, wherein said
first clasp has a shoulder supporting said collar.
14. The spinal implant system according to claim 12, wherein said
collar has two opposing and aligned indentations which are aligned
with a slot in said head to receive and support said spinal
rod.
15. The spinal implant system according to claim 12, wherein said
collar has an axial plane of symmetry which allows a mounting of
said second clasp using said connecting element.
Description
The invention presented here relates to spinal osteosynthetic
surgery and, more precisely, to vertebral osteosynthetic systems,
i.e. to those systems which are designed to immobilize at least two
adjacent vertebra relative to each other.
Among these systems, the invention involves those which include at
least one binding clip which is carried by a supporting instrument
extending over at least one part of the spinal column. This
supporting instrument can be a distraction or compression bar or a
plate. The binding clamp is made up of two clasps which are
designed to become fixed on either side of a vertebral projection,
for example, a peduncle, a blade, or a transverse apophysis, of a
same vertebra, and a connection component constructed to attach the
two clasps to each other at least in the direction of their mutual
extension.
BACKGROUND ART
Clips currently known, the connection component is made up of a
screw in which the head is immobilized unidirectionally on one of
the clasps and has a threaded shaft which is screwed into a tapped
bore of the body of the other clasp. A locking screw is screwed
into this body, transversally to the threaded shaft, in order to
immobilize the connection screw relative to it.
A binding clip of this type is of the automatic stable type, in the
sense that it can be placed on a vertebra in a stable manner due to
the fact that the two clasps are fixed on the vertebra and held in
place by the connection screw, while the support instrument is not
yet in place.
On the other hand, this binding clip presents a disadvantage which
lies in the fact that the user must work successively on two
screws, i.e. the connection screw and the locking screw. In so far
as the connection screw is concerned, the user must, on the one
hand, perfectly align this screw with the threaded body and, on the
other hand, for the proper threaded joint, must have recourse to a
complex instrument of the cardan drive screwdriver type, which is
less convenient. On the other hand, in so far as the locking screw
is concerned, it is more approachable and ensures a good transverse
locking of the connection component by tightening.
In addition, due to the fact that a connection screw is used, these
binding clips are cumbersome and bulky in height, which limits
their use.
SUMMARY OF THE INVENTION
The goal of correcting these disadvantages while keeping the
advantages of a locking screw and, for this purpose, the binding
clip according to the invention is characterized in that the
connection component includes a shaft which has a first end
immobilizable in at least one direction on one of the clasps and a
shank immobilizable on the other clasp; the aforementioned other
clasp having an extended receptacle for receiving the shank, this
receptacle being open at its two ends and opening out transversally
to the outside over its entire length between the two opposing
surfaces to allow a positioning and a removal at the side of the
connection component relative to the other clasp; and a locking
screw of the shank is formed in the receptacle, the axis of which
is perpendicular to the longitudinal direction of the receptacle
and which acts together with a tapped hole installed on the
opposing surfaces.
Thus, in the binding clip according to the invention, a shaft which
is threaded without a threaded joint in a receptacle, either
axially, or on the side, is used as the connection component. This
shaft is locked in position by the locking screw, and relatively
easy to access and manipulate. The control of the relative position
of the two clasps is done by the simple sliding of the connection
shaft relative to one of the clasps, the locking in a selected
position being done using the locking screw. In the system
according to the invention, it is not necessary to maneuver a screw
as the connection component.
According to a preferred embodiment mode, the receptacle is
combined with one of the clasps which is carried by the support
instrument.
The surface of the shank of the connection component is smooth or
has, at least in the area of the second end of the connection shaft
acting together with the receptacle, roughness, for example, a
knurling, striations, or notches.
The axis of the locking screw can be oblique or perpendicular with
respect to the plane defined by the parallel axes of the support
instrument and the connection shaft.
The receptacle can have a bottom having a semi-circular cross
section, corresponding to the diameter of the shank of the
connection component, extended towards the outside by the two
opposing surfaces which are preferably parallel.
One of the two clasps which is carried by the support instrument
can have a split threaded head for the reception of the support
instrument which is immobilized there by the nut. This nut, the
receptacle and the locking screw are preferably constructed so that
the nut prevents an untimely exit of the locking screw, which would
unlock the connection shaft. For example, the nut is supported on
the locking screw.
The first end of the connection component, which is fixed in at
least one direction on one of the clasps, has a cylindrical or
conical head which is received in a complementary receptacle
provided in the clasp which carries it and can be stopped against a
shouldering wall.
The receptacle for receiving the connection shaft can be arranged
in the body itself of the other clasp, or even in a collar which is
held united with the other clasp.
In the second case, this other clasp has, in an advantageous
manner, a supporting shoulder of the collar.
This collar preferably has an axial plane of symmetry which allows
its mounting, and therefore, the mounting of the clasp that it
carries, using the connection component, both to the right and to
the left of the support instrument, and of the clasp with which it
acts directly.
This collar can have two opposing and aligned indentations which
extend the slot of the head of the clasp to receive and support the
support instrument.
BRIEF DESCRIPTION OF THE DRAWINGS
Be understood well in reading the supplemental description which
follows,
of two preferred embodiment modes of the invention, and by
referring to the attached drawings which make up a part of the
description and in which:
FIG. 1 is an exploded perspective view showing the pieces making up
a binding clip constructed according to a first preferred
embodiment mode of the invention, connected to a support bar;
FIG. 2 is a perspective view showing only the connection component
mounted on one of the clasps;
FIG. 3 is, on a larger scale, an axial section along the line
III--III of FIG. 1, with a cut-away, showing the binding clip in
the assembled mounted state on the support instrument;
FIG. 4 is a lateral cut-away view of the binding clip and the
support instrument in the assembled state;
FIG. 5 is a planar view of the binding clip and the support
instrument in the assembled state; and
FIG. 6 is an exploded perspective view similar to FIG. 1, showing
the pieces making up a binding clip constructed according to a
second preferred embodiment mode of the invention, connected to a
support bar.
DETAILED DESCRIPTION OF THE INVENTION
In reference to the FIGS. 1 to 6 are the common characteristics of
the two preferred embodiment modes.
The binding clip according to the invention is designed to be fixed
on a vertebra (not shown), by a peduncle, a blade, or a transverse
apophysis of the vertebra, to immobilize it with respect to at
least one other vertebra using a support instrument 1, here a
distraction or compression bar.
In order to fix it onto the vertebra, the binding clip includes, as
shown best in FIGS. 1, 4, 5 and 6, two clasps, i.e. one main clasp
2 and an auxiliary or counter-clasp 3, which are open towards each
other and are connected to themselves, in at least one direction,
i.e. in the direction of their mutual extension, by a connection
component 4. Thus, the clasps 2 and 3 can be fixed on either side
of the accommodated vertebral projection, by being held there by
the connection component 4.
This connection component 4 includes a shaft which has an end or
head 5 constructed in order to be immobilized in at least the
direction indicated by the arrow A (FIG. 2) on the counter-clasp 3.
The head 5 is indicated in the form of a cylinder designed to be
received in a cylindrical receptacle 6 of the counter-clasp 3. The
receptacle 6 is open to the top and it extends over more than
180.degree. in order to be able to transversally hold the head 5 of
the shaft 4. The axial restraint of the head 5 is ensured by a
shoulder 7 positioned at the end of the receptacle 6, on the side
facing the main clasp 2. This shoulder 7 is designed to act
together with the base 8 of the head 5. This base also has a
connection shoulder with the shank 9 of the shaft 4. This shaft 4
has a diameter less than that of the head 5. The angular range of
the receptacle 6 is such that the shaft 4 can be engaged in the
receptacle 6, either axially or transversally, after which the
shaft 4 is displaced axially according to the arrow A of FIG. 2, so
that when the head 5 enters the receptacle 6, its base 8 is stopped
against the shoulder 7, and the shaft 4 being thus unified with the
counter-clasp 3 both transversally as well as in the direction of
the arrow A. As a variation, the receptacle 6 and the head 5 can be
conical, becoming slimmer going towards the shank 9, the shoulder
of the stop 7 thus no longer being necessary.
The main clasp 2, which is designed to receive the bar 1, has a
cylindrical head 10 with external threads 11, for the reception of
a nut 12, and, roughly over its entire height, a diametrical slot
13 having a size corresponding roughly to the diameter of the bar 1
for receiving it. This being the case, on the sides of the slot 13,
the head 10 can have a tapped hole 14 for receiving a mounting
tool.
The main clasp 2 has an extended receptacle 15 for receiving the
shank 9 of the connection component 4. This receptacle 15 is open
at its two ends and opens transversally to the outside over its
entire length between the two opposing surfaces 16 in order to
allow the positioning and removal at the side, of the connection
component 4 relative to the clasp 2. A locking screw 17 acts
together with the two threaded portions of a tapped hole 18
arranged on its surfaces 16. The locking screw 17 does not have a
head and it has a hexagonal operating recess 19.
In general, the shank 9 of the connection component 4 is
cylindrical and has a circular cross section; in this case, the
receptacle 15 has a base with semi-circular cross section having a
radius corresponding to that of the shank 9. The bottom of the
receptacle 15 is extended towards the outside by the two opposing
surfaces 16, which are preferably parallel.
The surface of the shank 9 of the connection component 4 can be
either smooth or has, at least in the area which is located at its
free end and which acts together with the receptacle 15 and the
locking screw 17, roughness, for example, a knurling, striations,
or notches, encouraging the support of the shank by friction when
the screw 17 is tightened.
The assembly is constructed such that when the connection component
4 is in its receptacle 15 and is fixed there by the locking screw
17, and when the support instrument 1 is in the diametrical slot 13
of the cylindrical head 10, the nut 12 fixes the support instrument
1 in the head 10 and, simultaneously, rests on the locking screw 17
in order to prevent an untimely exit of the nut by unscrewing.
As shown in FIGS. 1 and 3, the axis of the locking screw 17 can be
inclined with respect to the axis of the head 10 of the clasp 2.
However, as shown in FIG. 6, the axis of the screw 17 can be
parallel to the axis of the head 10 of the clasp 2. Moreover, the
axis of the locking screw 17 can be either perpendicular (FIGS. 1
and 3) or crosswise (FIG. 6) with respect to the plane defined by
the parallel axes of the support instrument 1 and the connection
component 4.
Now the characteristics peculiar to the embodiment mode of FIGS. 1
to 5 will be described.
In this embodiment, the extended receptacle 15, which is parallel
to the base of the diametrical slot 13 of the head 10, is formed
directly in the body 20 of the clasp 2. This body 20 has an
inclined edge 21 in projection allowing the definition of one of
the surfaces 16 extending the base of the receptacle 15 to the
outside.
As shown in FIGS. 3 to 5, when the shank 9 of the connection
component 4 is immobilized in the base of the receptacle 15 by the
locking screw 17 and the support instrument 1 is located at the
base of the diametrical slot 13, in parallel relation to the shank
9, the nut 12, equipped with notches 22, simultaneously rests on
the support instrument 1 and on the free outside end of the locking
screw 17 in order to ensure both the immobilization of the support
instrument 1 and the locking of the locking screw 17, and
therefore, of the connection component 4.
Now the characteristics peculiar to the embodiment mode of FIG. 6
will be described.
In this embodiment, the receptacle 15 is arranged, not in the body
20 of the clasp 2, but in a separate collar 23 designed to be
immobilized on the body of the clasp 2 by the nut 12. This collar
is of a generally rectangular appearance, and it has a central bore
24 for its mounting without play on the head 10 of the main clasp
2. The receptacle 15 rests on a shoulder 25 formed on the head 10
integrally with the body 20. The front of the collar 23 which is
opposed to the support face on the shoulder 25 has two indentations
26 opposed and aligned which open into the central bore 24 and
which are aligned with the sides of the diametrical slot 13 of the
head 10. These indentations have a semi-circular configuration with
a radius, equal to that of the bar 1. Due to the fact that the slot
13 of the head 10 extends roughly axially to the shoulder 25, the
bar 1 is supported on the bottom of the indentations 26 and,
transversally, it is in contact with the sides of the slot 13,
which prevents rotation of the collar.
In order to receive the shank 9 of the connection component 4, the
collar 23 is set eccentrically with respect to its central bore 24,
and the receptacle 15 is arranged with its eccentric part parallel
to the indentations 26.
The collar 23 has an axial plane of symmetry, perpendicular to the
axis of the receptacle 15.
The assembly is constructed such that after assembly the nut 12
rests simultaneously on the support instrument 1 and on the locking
screw 17, without contact with the collar 23. The nut 12 can have
notches 22 on its threaded face. By resting on the support
instrument 1, it pins the support instrument in the notches 26,
which pushes the collar 23 against the shoulder 25; at the same
time, it rests on the locking screw 17, while preventing its
untimely exit by unscrewing.
With respect to the embodiment mode of FIGS. 1 to 5, the embodiment
mode of FIG. 6 requires a supplementary piece, i.e. the collar 23,
but it has the advantage of allowing a positioning of the
connection component 4, and therefore, of the counter-clasp 3, to
the left or to the right with respect to the main clasp 2, and this
is due to the fact that the collar 23 can take up two positions
180.degree. apart.
In order to position the binding clip, prior to positioning the
support instrument 1, the connection component 4 and the
counter-clasp 3 are assembled, as shown in FIG. 2, and the shank 9
of the connection component 4 is placed in the receptacle 15,
either axially, or transversally, due to the fact that the
receptacle 15 is open on the side along its entire length. The
clasps 2 and 3 are then placed on either side of the vertebral
projection involved, this positioning is accompanied by a free
sliding of the shank 9 in the receptacle 15. For this positioning,
the user can, for example, use a compression binding clip, the jaws
of which take hold on the back of the clasp 3 and on a notch,
groove, or the like 28 formed at the free end of the shank 9. After
the desired position of the clasps has been obtained, they are
locked in place by screwing the locking screw 17. Thus, one obtains
a stable mounting of the two clasps on the vertebral projection,
even though the support instrument 1 is not yet in place.
Later, after the placement by the user of other components for
affixing on the spinal column, the support instrument 1 can be put
in place and then immobilized by its penetration in the slot 13 of
the main clasp 2 and the indentations 26 of the collar 23, after
which the nut 12 is screwed on, for example, using a gripping tool
acting together with the notches 27 arranged on the nut 12.
When the nut 12 is screwed in, this nut is supported on the support
instrument 1 in order to lock against the bottom of the
indentations 26 and, at the same time, it rests on the locking
screw 17.
Of course, the invention is not limited to the embodiment modes
which have been described; on the contrary, different variations
can be conceived without necessarily leaving its frame. The
foregoing disclosure and description of the invention is
illustrative and explanatory thereof. Various changes in the
details of the illustrated apparatus may be made within the scope
of the appended claims without departing from the true spirit of
the invention. The present invention should only be limited by the
following claims and their legal equivalents.
* * * * *